// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef STORAGE_BROWSER_FILE_SYSTEM_SANDBOX_FILE_STREAM_READER_H_
#define STORAGE_BROWSER_FILE_SYSTEM_SANDBOX_FILE_STREAM_READER_H_

#include <stdint.h>

#include <memory>

#include "base/bind.h"
#include "base/component_export.h"
#include "base/files/file.h"
#include "base/memory/raw_ptr.h"
#include "base/memory/ref_counted.h"
#include "base/time/time.h"
#include "net/base/completion_once_callback.h"
#include "storage/browser/blob/shareable_file_reference.h"
#include "storage/browser/file_system/file_stream_reader.h"
#include "storage/browser/file_system/file_system_url.h"

namespace base {
class FilePath;
}

namespace storage {

class FileSystemContext;

// FileStreamReader implementation for Sandboxed FileSystem files.
// This wraps either a LocalFileStreamReader or a MemoryFileStreamReader,
// depending on if we're in an incognito profile or not.
class COMPONENT_EXPORT(STORAGE_BROWSER) SandboxFileStreamReader
    : public FileStreamReader {
 public:
  // Creates a new reader for a filesystem URL |url| from |initial_offset|.
  // |expected_modification_time| specifies the expected last modification. if
  // the value is non-null, the reader will check the underlying file's actual
  // modification time to see if the file has been modified, and if it does any
  // succeeding read operations should fail with ERR_UPLOAD_FILE_CHANGED error.
  SandboxFileStreamReader(FileSystemContext* file_system_context,
                          const FileSystemURL& url,
                          int64_t initial_offset,
                          const base::Time& expected_modification_time);

  SandboxFileStreamReader(const SandboxFileStreamReader&) = delete;
  SandboxFileStreamReader& operator=(const SandboxFileStreamReader&) = delete;

  ~SandboxFileStreamReader() override;

  // FileStreamReader overrides.
  int Read(net::IOBuffer* buf,
           int buf_len,
           net::CompletionOnceCallback callback) override;
  int64_t GetLength(net::Int64CompletionOnceCallback callback) override;

 private:
  friend class FileStreamReader;

  int CreateSnapshot();
  void DidCreateSnapshot(base::File::Error file_error,
                         const base::File::Info& file_info,
                         const base::FilePath& platform_path,
                         scoped_refptr<ShareableFileReference> file_ref);
  void OnRead(int rv);
  void OnGetLength(int64_t rv);

  raw_ptr<net::IOBuffer> read_buf_;
  int read_buf_len_;
  net::CompletionOnceCallback read_callback_;
  net::Int64CompletionOnceCallback get_length_callback_;
  scoped_refptr<FileSystemContext> file_system_context_;
  FileSystemURL url_;
  const int64_t initial_offset_;
  const base::Time expected_modification_time_;
  std::unique_ptr<FileStreamReader> file_reader_;
  scoped_refptr<ShareableFileReference> snapshot_ref_;
  bool has_pending_create_snapshot_;
  base::WeakPtrFactory<SandboxFileStreamReader> weak_factory_{this};
};

}  // namespace storage

#endif  // STORAGE_BROWSER_FILE_SYSTEM_SANDBOX_FILE_STREAM_READER_H_
